While the rise in obesity over the past 30 years has coincided with the rise in soft drink consumption, soft drinks represent only 7 percent of energy intake among adults. The case may be made for focusing on reducing soda consumption among the younger age groups, as obesity during childhood predicts adult obesity and concomitant health problems.

Based on insights from tobacco and alcohol taxation, a soft drink tax would reduce consumption only slightly. Moderate consumers, rather than heavy consumers, are the ones who respond to higher taxes. And, to the extent that individuals can substitute an untaxed high-calorie drink for a taxed one, the tax would not be effective in reducing obesity.

Other policies, in addition to taxes, might be more effective in reducing sugar-sweetened soda consumption, for example:

Reduce access to soft drinks in schools and vending machines.

Inform the public about the health consequences of consuming too many calories.

Increase physical activity.

The researchers conclude that “Motivating soft drink policies as a way to improve multiple areas of population health, instead of a method to reduce obesity, more accurately reflects the likely outcomes of the implementation of such policies.”